Atomizer



5. w. TULLIS ATOMIZER June 9, 1942.

Filed Jan. 12, 1940 1 /5 /2 nmllllllll o 40 mm!- 54 INVENTOR fioyd W721/05,

ATTOR'NEY Patented June 9, 1942 ATOMIZER Boyd W. Tullis, Wichita, Kans.,assignor to The Coleman Lamp and Stove Company, Wichita, Kans, acorporation of Kansas Application January 12, 1940, Serial No. 313,562

6 Claims.

This invention relates to fuel atomizers particularly for startingliquid hydrocarbon burning appliances which require generators forvaporizing the fuel. It is common practice to provide such applianceswith preheaters of the atomizer type and which are supplied with fueland air from a fount of the appliance, but these atomizers have not beendependable principally because of insumcient atomization and irregularair flow which results in a low temperature, smoky and unstable flame.Such devices have also been expensive and difficult to manufacture,especially as to machining of the air and fuel orifices in the bodyparts of the atomizer. The critical character of these orifices requirescomplete replacement of the parts when the orifices are enlarged throughcleaning or erosion so that upkeep of the appliance is expensive for theuser.

The principal objects of the invention are,

therefore, to provide an atomizer structure which more eifectivelyatomizes the fuel, producing a better mixture and giving a hotter, moreuniform, and dependable flame; to provide an atomizer structure which iscapable of inexpensive and accurate manufacture; to provide an atomizerhaving removable tips so that it is only necessary to replace the tipswhen the orifices become enlarged or clogged; and to provide aconstruction wherein the atomizer parts and orifices may be accuratelyformed so that the parts may be standardized and the tips replaced atsmall cost to the user.

It is a further object of the invention to effect atomization of thefuel by multiple stages, each stage being progressively efiected toproduce finer,

tures of the present invention, a part of the fount' 1.

being broken away to better illustrate the pump and fuel supply tube tothe atomizer.

Fig. 2 is an enlarged section through the atomizer.

Fig. 3 is a horizontal section on the line 3-3 of Fig. 2.

Fig. 4 is a detail perspective view of the fuel mixture discharge tipand its retaining parts shown in disassembled spaced relation.

Fig. 5 is a similar view showing the air and I fuel tip with itsretaining parts in disassembled spaced relation.

Referring more in detail to the drawing:

I designates a liquid fuel hydrocarbon burning appliance which may be alantern as shown, in which case the appliance includes a fount 2 forcontaining the liquid fuel, such as kerosene, under pressure generatedby a pump 3. The appliance also includes a generator 4 for vaporizingthe fuel which is delivered from the fount through a tube 5 undercontrol of a valve 6, the generator 4 being located within the heat zoneof the consumed fuel which, in the illustrated instance, is a mantle 1.

In initially starting the appliance, it is necessary to preheat thegenerator and this is eifected by a preheater 8 including a vaporizer 9supplied with fuel and air under pressure from the fount, as now to bedescribed. The vaporizer assembly includes a sleeve-like nipple l0threaded into an opening at the top of the fount and which has athreaded neck II for mounting a valve body I2 containing an atomizingtip IS, a discharge tip [4, and a closure cap I5 carrying a nozzle-likemixing tube I6 which directs a flame against the generator 4. The valvebody l2 has an internally threaded skirt I! for engaging threads of theneck ll. Formed within the valve body are coaxially stepped cylindricalbores l8, I9 and 29 to form a clamping shoulder 2i and annular fuelimpacting surfaces 22 and 23 which are arranged in planes transverselyof the axis of the bores and concentric with a port 24 extending to abore 25 formed in a threaded neck 26 on the upper end of the valve body.The valve body also includes a laterally extending threaded branch 21having an axial bore 28 terminating in a coneshaped valve seat 29intersecting the port 24. The axial bore 28 is internally threaded toaccommodate the threaded stem 3!! of a coneshaped valve 3! which isadapted to be moved to and from the cone-shaped seat 29 upon actuationof a hand-wheel 32 fixed to the outer end of the stem 32!. The threadedbranch 21 carries a packing nut 33 for compressing a packing 34 aboutthe valve stem 30.

The cap [5 is carried on the threaded neck 26 of the valve body and hasinternal threads 35 engaging the threads of the neck and which isprovided with an annular shoulder 36 to seat the lower end of thenozzle-like mixing tube Iii. The closure cap I5 also includes anon-critical outlet orifice 3'! located in axial alignment with theoutlet port and through which atomized fuel is discharged for combustionin the tube when the mixture is lighted through an opening 38 that isformed in the side of the tube as clearly shown in Figs. 1 and 2.

The atomizing tip I3 is a separate part from the valve bod and nippleand is clamped therebetween. The atomizing tip l3 includes a diskportion 39 snugly received Within the bore l8 and which is provided witha flat upper face 40 engaged with the clamping shoulder 2| andcooperating with the annular fuel impacting surface 22 to form anannular air distributing space 4| therebetween. The lower face of thedisk portion has an annular rib 42 which is engaged by the end face ofthe neck II when the valve body and nipple are screwed together, therebyspacing the central, lower portion of the disk from the nipple toprovide an annular passageway 43 having direct connection with the bore44 of the sleeve-like nipple l9.

Formed coaxially with the disk portion 39 and extending from therespective sides thereof are cylindrical portions 45 and 46 having abore 41 opening from the end of the cylindrical portion 45 butterminating short of the end of the cylindrical portion 45 as shown inFig. 2, leaving a relatively thin end wall 48 that is provided with anorifice 49 which controls flow of fuel. Threaded in the open end of thebore is a tube 50 leading to the bottom of the fount for conducting theliquid fuel to the tip I3. The oylindrical portion 45 of the tip extendswithin the bore 29 which cooperates therewith to provide an annular airpassageway 5| extending in the direction of the impact surface 23. Theupper end of the cylinder portion 45 terminates short of the surface 23to form an atomizing chamber 52.

Air is delivered from the fount through the bore 44 to the annularpassageway 43 from where it is discharged through a bore 53 connectingwith an orifice 54 formed in the thinner part of the disk portion 39 andin line with the space 4|, the orifice 54 being arranged to dischargeair against the annular surface 22 so that it is divertedcircumferentially of the air distributing space 4| whereby the air flowsuniformly into the passage 5| around the periphery of the cylindricalportion 45 of the tip. Upon striking the surface 23 the air is divertedlaterally and transversely across the stream of fuel discharged throughthe orifice 49 to break up the fuel and effect atomization thereof inthe chamber 52. The atomized fuel and air are then delivered as amixture through the port 24.

The port 24 is of relatively small bore to faoilitate contact by theliquid portion of the mixture causing break down of the liquid globuleson the metal surface in the form of a thin film. This filming isefiected because the metal surface has a greater adhesion for oil thanthe cohesion force holding the oil in globule form. The erosive force ofthe moving mixture in contact with the oil film effects very minuteatomization. To be effective, the port 24 should be of considerablelength in ratio to the bore so that all the globules discharged from theatomizing chamber have opportunity to break down in the form of a film.This port extends into the tip l4 so that it may be more accurately andeconomically drilled since a portion thereof is in the body and theupper portion is formed in a separate part, thereby providing shorterdrilling operations but giving the length required for attaining thedesired results.

The tip I4 includes a cylindrical body 55 snugly engaged within the bore25, a lower end abutting against the bottom of the bore 25. The bore 58in the tip terminates short of the upper end thereof to provide a thinend wall 59 having an orifice 60 of sufficiently small diameter toproduce a small jet of the atomized mixture at sufficiently highvelocity to produce a Bunsen-like effect in the nozzle tube.

In operating a vaporizer constructed and assembled as described,pressure is built up in the upper portion of the fount by actuating thepump 3. The hand-wheel 32 of the shut-off valve is then rotated to openthe port 24 and effect release of pressure from the fount through thebore 44, the annular passageway 43, and orifice 54, so that a jet of airis discharged against the surface 22 and distributed in the space 4|uniformly about the periphery of the cylindrical portion 45 to moveupwardly through the annular passageway 5| and impinge against thesurface 23 to be diverted laterally at right angles into the atomizingchamber 52 and across the jet of liquid fuel discharged through theorifice 49, under pressure of the air acting on the surface of theliquid in the fount. This lateral movement of the air from alldirections across the stream of liquid effects atomization thereof, andresults in an atomized mixture discharged into ports 24 and 58, wherethe filming action of the oil globules effects more completeatomization, and the more thoroughly atomized mixture is dischargedthrough the orifice 69 into the mixing nozzle 16. When the mixture isignited, it burns with a uniform, steady flame of intense heat toquickly preheat the generator. When the generator is heated the valve 6is opened and the fuel flowing therethrough is vaporized and readilyignitable when discharged into the mantle. When the fuel is vaporizedsufficiently to operate the mantle, the valve 3! is closed to shut offflow of liquid fuel through the tube 50 and prevent discharge of airthrough the atomizer.

It is obvious that by constructing the tips separately from the bodyportions of the atomizer, they are cheaper to manufacture and thecritical orifices therein may be more accurately formed. The separatetips also provide ready replacement of these parts so that it is notnecessary to replace the major parts of the atomizer.

It is also obvious that by uniformly distributing the air about thepassageways and effecting lateral flow uniformly across the orifice ofthe atomizing tip, supplemented by the filming action on the metalsurfaces of the ports 24 and 5B, the atomization effect is efficient anda readily ignitable mixture is produced with a uniform flow of air andfuel at the pressure carried within the fount, thereby providing astable flame which plays smoothly on the generator and which is free ofsmoke and odors usually resulting from improper atomization.

What I claim and desire to secure by Letters Patent is:

1. In a device of the character described, a body member having steppedbores forming a shoulder therebetween, an atomizing tip having a diskportion in the larger of said bores, means spacing the disk portion fromsaid shoulder to form an annular air distributing space therebetween, acoaxial cylindrical portion projecting from said disk portion of theatomizing tip and having exterior surfaces thereof spaced fromcorresponding surfaces of the smaller of the bores to form an initialatomizing chamber and an annular passageway connecting the airdistributing space with said initial atomizing chamber, means supplyingliquid fuel to said atomizing tip for discharge through an axial orificein the cylindrical portion thereof, said disk portion of the atomizingtip having an air discharge orifice connecting with said airdistributing space, means retaining said disk portion in fixed positionwithin said body member and forming a connection to a pressure chamberfor supplying air to said last named orifice, a discharge tip having anelongated bore registering with an axial bore in said body member toform a fuel break-down chamber and provided with a restricted dischargeorifice to effect retardation of droplets of liquid fuel and cohesionthereof on the wall surface of the break-down chamber, and a capremovably retaining said last named tip.

2. A device for atomizing a liquid hydrocarbon including a body memberhaving stepped bores in one end thereof, an atomizing tip in said bodymember having portion corresponding to said bores to form airpassageways and a mixing chamber therebetween, a nippl connected withthe body member for retaining the atomizing tip in fixed position withinsaid body member, said body member having an elongated smaller boreaxially connecting said stepped bores with a bore at the opposite end ofsaid body member to form a vaporizing chamber in connection with themixing chamber, a tip in said last named bore having a port registeringwith said vaporizing chamber, a retaining cap connected with the bodymember for retaining the last named tip, a valve in said body member forcontrolling flow through said vaporizing chamber, said atomizing tiphaving an air discharge orifice connected with the air passageways, anda tube extending through said nipple and connected with the atomizingtip for supplying a liquid hydrocarbon to said tip.

3. In a device for atomizing a liquid fuel, a body member having axialbores in opposite ends thereof connected by a smaller bore extendingthrough said body member, the wall of said smaller bore forming a filmcollecting surface, a fuel atomizing tip removably mounted in one ofsaid end bores, said end bore mounting the atomizing tip having steppedportions cooperating with corresponding portions of the tip to form anair passageway terminating at the outlet of said tip in a mixing chamberdischarging into the smaller bore, a fuel mixture discharge tipremovably mounted in the other bore and having a restricted dischargeorifice, means clampingly retaining said tips in the respective bores,means supplying liquid fuel to the atomizing tip, and means supplyingair to said passageway for intersecting the liquid discharged from saidtip in the mixing chamber to atomize said fuel and for picking upparticles of said film from the wall of the smaller bore.

4. In a device for atomizing a liquid hydrocarbon, a body member havingstepped bores forming an annular shoulder therebetween, said smallerbore being terminated by an end wall having an orifice therethrough, anatomizing tip having a disk portion in the larger of said bores, meansspacing said disk portion from said shoulder to form an annular airdistributing space, a coaxial cylindrical portion projecting from saiddisk portion of the tip and having an end face spaced from said end wallto form an atomizing chamber and having a circumferential surface spacedfrom the corresponding surface of the smaller of the bores to form anannular passage connecting the air distributing space with the atomizingchamber, means supplying liquid hydrocarbon to said tip for dischargethrough an axial orifice in the cylindrical portion thereof, said diskportion of the tip having an air discharge orifice connecting with saidair distributingspace, and means retaining said disk portion in fixedposition within said body member.

5. In a device of the character described, a body member having a seriesof stepped bores forming a shoulder therebetween, said smaller borebeing terminated by an end wall having an orifice therethrough, anatomizing tip having a disk portion in the larger of said bores, meansspacing said disk portion from said shoulder to form an annular airdistributing space therebetween, a coaxial cylindrical portionprojecting from said disk portion of the tip having an end face spacedfrom said end wall to form an atomizing chamber and having acircumferential surface spaced from the corresponding surface of thesmaller bore to form an annular passage connecting the air distributingspace with the atomizing chamber, means supplying a liquid to said tipfor discharge through an axial orifice in the cylindrical portionthereof, said disk portion of the tip having an air discharge orificeconnecting with said air distributing space, and a nipple havingthreaded connection with th body member and having an end retaining thedisk portion in fixed position, said nipple forming a connection to apressure chamber for supplying air to said last named orifice.

6. A device for atomizing a liquid hydrocarbon including, a body memberhaving a mixing chamber and a liquid break-down chamber of smallerdiameter than the mixing chamber and having coaxial connectiontherewith, mean for admitting a liquid hydrocarbon and an atomizingmedium into the mixing chamber for effecting initial atomization of theliquid hydrocarbon, said break-down chamber being located in the path ofatomized liquid and said medium so that droplets of liquid hydrocarboncontact the wall of the break-down chamber to effect atomization of saiddroplets and spreading thereof in a thin film on said wall to be pickedup by scouring action of said medium moving through said break-downchamber for effecting further reduction of said liquid hydrocarbon, saidbody member having a recess coaxial of the break-down chamber at the endopposite said coaxial connection, a tip in said recess having a boreforming a continuation of the break-down chamber and having a restricteddischarge orifice, and means connected with the body member to retainthe tip in said recess.

BOYD W. TULLIS.

